Paul imhoff



rrn STATES ATENT OFFICE.

PAUL IllIl-IOFF, OF LIVERPOOL, ENGLAND, ASSIGNOR TO THE UNITED ALKALI COMPANY, LIMITED, OF SAME PLACE.

PROCESS OF MAKING OXY HALOGEN SALTS.

SPECIFICATION forming part of Letters Patent N 0. 627,000, dated June 1 3, 1899.

Application filed November 11, 1898.

To all whom it may concern:

Be it known that I, PAUL IMHOFF, Ph.D., chemist, a subject of the German Emperor, and a resident of No. 18 Greenbank road, Sefton Park, Liverpool, in the county of Lancaster, England, have invented certain new and useful Improvements in the Manufacture of Oxyhalogen Salts, (for which I applied for a patent in Germany onthe 28th day of March, 1898,) of which the following is a specification.

In the manufacture of salts of the oxyhalogen acids (such as hypochlorites, chlorates, and the like) by the electrolysis of alkaline or alkaline-earth chlorids in cells in which no diaphragm is employed secondary reactions leading to undesirable results are liable to occur.

The first action of the current in the electrolysis of the alkaline chlorid or alkalineearth chlorid liberates at the cathode a certain quantity of the electropositive ion and at the anode an equivalent quantity of chlorin. The potassium ion liberated at the cathode when potassium chlorid is electrolyzed reacts, further,with the water present to form caustic potash, hydrogen being liberated at the same time. The hypochlorite or chlorate results, as is Well known, by the interaction of the chlorin and caustic alkali present in the solution. Now this caustic alkali present in the solution also takes part in the conduction of the current, liberating at the cathode, by secondary reaction, hydrogen and at the anode oxygen, caustic alkali being again regenerated. The extent to which such conduction takes place corresponds practically to a decomposition of water by the current, and that portion of the current so working must therefore be regarded as lost. According to my invention I propose to overcome this difficulty, caused by the caustic alkali in solution taking part in the conduction of the current, by

Serial No. 696,135. (No specimens.)

adding to the solution an oxid which can act both as a basic and an acid radicalas, for example, oxid of aluminium (Al O )and which will form with the caustic alkali a compound requiring for its decomposition a current of higher electromotive force than the original caustic alkali; but being at the same time a compound basic in its character and capable of being acted upon by the chlorin to form the oxyhalogen salts with liberation of the A1 0 or corresponding oxid the reactions taking place are as follows:

The invention is not limited to the use of aluminic oxid, (Al O as any other oxid, such as boron trioxid or the like, which will act in the manner described, may be employed.

Having now particularly described and ascertained the nature of this invention and in what manner the same is to be performed, I declare that what I claim is The process of making oxyhalogen saltsof the alkali metals which consists in passing an electric current through a bath consisting of a solution of analkali-metal chlorid in which is suspended a metallic oxid which can act both as a basic and as an acid radical, thereby In testimony whereof I have. gned this specification in the presence of two subscribing witnesses.

I PAUL IMHOFF.

Witnesses:

FREDERICK JAMES HAWKINs, ALFRED PATOHETT. 

